Metabolic Pathways

Question 1

What term is the total of all the chemical reactions that an organism performs?

Answer 1

Metabolism

Question 2

Describe anabolism

Answer 2

Chemical reactions involved in building biological molecules

Question 3

Anabolism is what type of chemical reaction?

Answer 3

Dehydration/condensation synthesis reaction (endothermic)

Question 4

Describe catabolism

Answer 4

Chemical reactions that break down complex molecules into simpler compounds

Question 5

Catabolism is what kind of chemical reaction?

Answer 5

Hydrolysis (exothermic)

Question 6

What are the primary purposes of carbohydrates

Answer 6

Energy storage and structural purposes in plants and insects

Question 7

What is the chemical composition of monosaccharides?

Answer 7

Carbon, hydrogen, and oxygen in a 1:2:1 ratio (all monosaccharides are structural isomers of each other)

Question 8

How many carbons does a monosaccharide chain have?

Answer 8

3 to 9 (triose, tetrose, pentose, hexose, etc.)

Question 9

What functional group is present in monosaccharide molecules?

Answer 9

Carbonyl group (aldehyde or ketone)

Question 10

What is the most abundant molecule on the planet?

Answer 10

Cellulose

Question 11

Describe what happens when a monosaccharide with five or more carbons is dissolved in water

Answer 11

It forms a ring configuration with an alpha and beta configuration

Question 12

Draw an α-D-glucose molecule

Answer 12

Down, down, up, down, up

Question 13

Draw a β-D-glucose molecule

Answer 13

Up, down, up, down, up

Question 14

Draw a straight-chain glucose molecule

Answer 14

H — C = O
|
H — C — OH
|
HO — C — H
|
H — C — OH
|
H — C — OH
|
H — C — OH
|
H

Question 15

Draw a straight-chain galactose molecule

Answer 15

H — C = O
|
H — C — OH
|
HO — C — H
|
OH — C — H
|
H — C — OH
|
H — C — OH
|
H

Question 16

Draw a straight-chain fructose molecule

Answer 16

H
|
H — C — OH
|
C = O
|
HO — C — H
|
H — C — OH
|
H — C — OH
|
H — C — OH
|
H

Question 17

Describe the function of a glucose molecule with an alpha configuration

Answer 17

Common in animals, used for energy and storage

Question 18

Describe the function of a glucose molecule with a beta configuration

Answer 18

Common in plants, used for structure and support

Question 19

What is the difference between an α-D-glucose molecule and a β-D glucose molecule?

Answer 19

The hydroxyl group on carbon-1 is below the plane in an alpha configuration, and above the plane in a beta configuration

Question 20

What type of chemical reaction do monosaccharides undergo?

Answer 20

Condensation/dehydration reaction synthesis

Question 21

Which two monosaccharides react to form maltose?

Answer 21

Two glucose molecules

Question 22

Which two monosaccharides react to form sucrose?

Answer 22

Glucose and fructose

Question 23

Which two monosaccharides react to form lactose?

Answer 23

Glucose and galactose

Question 24

What specific chemical reaction do two glucose molecules undergo in the formation of maltose?

Answer 24

α-1,4 glycosidic linkage (condensation synthesis reaction)

Question 25

Draw the chemical reaction which results in the formation of maltose

Question 26

Describe the solubility of carbohydrates

Answer 26

Monosaccharides and disaccharides are readily soluble in water, therefore easily transported in blood. Polysaccharides are generally insoluble

Question 27

What are the most important polysaccharides made of glucose monomers?

Answer 27

Glycogen, starch, cellulose

Question 28

What monomer comprises polysaccharides such as glycogen, starch, and cellulose?

Answer 28

Glucose

Question 29

What differentiates polysaccharides?

Answer 29

Arrangement of bonds between glucose units, branching patterns, and total number of glucose subunits

Question 30

What is the function of glycogen?

Answer 30

Stored form of energy in animals, found in the muscles and liver

Question 31

Describe the chemical composition of glycogen

Answer 31

Composed of α glucose subunits held together by α (1,4) linkages. Branches occur every 8-10 glucose units with α (1,6) linkages at the branch points

Question 32

Describe the function of starch

Answer 32

Stores energy in plants

Question 33

What are the two forms of starch?

Answer 33

Amylose and amylopectin

Question 34

Describe the chemical composition of amylose

Answer 34

Unbranched chain of α (1,4) linkages

Question 35

Describe the chemical composition of amylopectin

Answer 35

A branched polymer similar to glycogen but with fewer branch points of α glucose subunits linked by α (1,4) in the chain and α (1,6) at the branch

Question 36

Which polypeptide is similar to glycogen, but with fewer branch points?

Answer 36

Amylopectin

Question 37

Which polysaccharide is composed of α glucose subunits held together by α (1,4) linkages and have branches occurring every 8-10 glucose units with α (1,6) linkages at the branch points

Answer 37

Glycogen

Question 38

Which polysaccharide is an unbranched chain of α (1,4) linkages?

Answer 38

Amylose

Question 39

Which polypeptide is a branched polymer with α glucose subunits linked by α (1,4) in the chain and α (1,6) at the branch?

Answer 39

Amylopectin

Question 40

Draw a model of a glycogen chain

Question 41

Draw a model of an amylose chain

Question 42

Draw a model of an amylopectin chain

Question 43

Describe the function of cellulose

Answer 43

The structural material of plants cell walls, allowing for much plant growth

Question 44

Describe the chemical composition of cellulose

Answer 44

Made of long, straight chains of β glucose subunits joined by β (1,4) linkages. Every second monomer of glucose has a flipped orientation

Question 45

How are cellulose fibres formed?

Answer 45

Hydrogen bonds occur between parallel chains of cellulose

Question 46

Why can humans not digest cellulose?

Answer 46

Every second β glucose monomer in cellulose has a flipped orientation. This pattern is unrecognizable by enzymes so it cannot be broken down

Question 47

Describe the function of chitin

Answer 47

Makes up the external skeletons of insects, spiders, crabs, shrimp, etc.

Question 48

Describe the chemical composition of chitin

Answer 48

Structural polymers made of amino sugars linked by β (1,4) bonds

Question 49

Draw a model of a cellulose chain